The Children's Hospital of Philadelphia (CHOP) and St. Christopher's Hospital for Children (SCHC), currently linked through the Circle of Care, a HRSA Pediatric AIDS Demonstration Project, propose to form a Philadelphia Pediatric AIDS Clinical Trials Unit. The two institutions will enroll at least 50 human immunodeficiency virus-infected children per year in phase I, phase II, and phase III trials. Subjects will be recruited from existing patient populations and through community outreach efforts by culturally sensitive individuals. Obstetrical and perinatal research will be conducted at hospitals allied and/or associated with the two pediatric hospitals: Temple University Hospital with SCHC, Thomas Jefferson University Hospital and the Hospital of the University of Pennsylvania with CHOP. Pregnant women and children of minority groups, predominantly African-Americans and Latinos, will comprise close to 90% of the patient population. Recruitment of drug abusers and their children will be facilitated by our consortium arrangement. Hemophiliac children will also be included in clinical studies. The proposed Philadelphia Pediatric ACTU will facilitate basic, as well as clinical research; and provide ancillary services for HIV-infected children and their families, in addition to fulfilling its primary mission as a clinical trials unit.